Re: JESS: Jess determinism
"Ernest Friedman-Hill" <[email protected]> Thu, 10 Feb 2011 20:58:09 -0500
| Newsgroups | gmane.comp.java.jess |
|---|---|
| Message-ID | <[email protected]> |
Jess doesn't have much (if any) use for hashing things using Object.hashCode() without overriding it. On Feb 10, 2011, at 11:11 AM, Skeptic . wrote: > > > Is the hashing based on Object.hashcode() or is it custom ? > Because, in practice, Object.hashcode() can be considered *random*. > >> From: [email protected] >> To: [email protected] >> Subject: Re: JESS: Jess determinism >> Date: Wed, 9 Feb 2011 20:45:54 -0500 >> >> >> On Feb 9, 2011, at 2:38 PM, Skeptic . wrote: >> >>> >>> Hi, >>> >>> By default, is the firing order deterministic? (i.e. rules fired in >>> the same order if the same WM is given). >>> >>> Also, is the order of the facts produced by the next method on a >>> QueryResult deterministic? (i.e. if I run the same defquery twice on >>> the same WM, I get the same facts in the same order) >> >> >> Jess's behavior is in no way *random*, which means it's completely >> deterministic. But the order in which these things occur is >> *undefined*, which means that it is determined by a number of >> factors, >> some of which are not visible to you. One of those factors is the >> number of hash buckets in the various node memories; if a node memory >> is rehashed, then the order may change within a given session. >> >> But if you run a single-threaded Jess program twice, starting from >> scratch, and execute the exact same sequence of commands both times, >> then you will get the exact same results. >> >> >> >> --------------------------------------------------------- >> Ernest Friedman-Hill >> Informatics & Decision Sciences, Sandia National Laboratories >> PO Box 969, MS 9012, Livermore, CA 94550 >> http://www.jessrules.com >> >> >> >> >> >> >> >> -------------------------------------------------------------------- >> To unsubscribe, send the words 'unsubscribe jess-users [email protected] >> ' >> in the BODY of a message to [email protected], NOT to the list >> (use your own address!) List problems? Notify [email protected] --------------------------------------------------------- Ernest Friedman-Hill Informatics & Decision Sciences Phone: (925) 294-2154 Sandia National Labs PO Box 969, MS 9012 [email protected] Livermore, CA 94550 http://www.jessrules.com -------------------------------------------------------------------- To unsubscribe, send the words 'unsubscribe jess-users [email protected]' in the BODY of a message to [email protected], NOT to the list (use your own address!) List problems? Notify [email protected]. --------------------------------------------------------------------